TORONTO – Liberal Leader Justin Trudeau apologized Wednesday for wearing brownface makeup at a party in 2001, after TIME Magazine published a photo from the event.

“I shouldn’t have done that. I should have known better but I didn’t and I’m really sorry,” Trudeau told reporters on the plane after a day of campaigning in Atlantic Canada.

TIME reported Wednesday that the photo appeared in the 2000-2001 yearbook of West Point Grey Academy, a private day school in Vancouver where Trudeau was a teacher at the time.

The photo was taken at the school’s annual dinner, which had an “Arabian Nights” theme, a Liberal Party spokesperson said.

Trudeau acknowledged that he was dressed as Aladdin.

"It was a dumb thing to do. I’m disappointed in myself. I’m pissed off at myself for having done it. I wish I hadn’t done it, but I did it and I apologize for it,” he said.

“I have worked all my life to try and create opportunities for people, to fight against racism and intolerance, and I can just stand here and say that I made a mistake when I was younger and I wish I hadn’t.”

Trudeau was nearly 30 years old when the photo was taken.

TIME said it obtained a copy of the yearbook from a Vancouver businessman who first saw the photo in July and “felt it should be made public.”

Asked whether this is the only such incident from his past, Trudeau said:  “When I was in high school, I dressed up at a talent show and sang Day-O. With makeup on.”

He was referring to “Banana Boat Song (Day-O),” a Jamaican folk song. The best-known version of it was released by Jamaican-American singer Harry Belafonte in the 1950s.

Late Wednesday, CTV's Question Period host Evan Solomon tweeted an image of that incident.

Asked if he should resign, Trudeau suggested that “mistakes” should be judged on a “case-by-case basis.”

"It was something that I didn't think was racist at the time, but now I recognize it was something racist to do, and I'm deeply sorry," he said.

Scheer says photo shows Trudeau ‘not fit to govern’

In a brief statement in front of cameras late Wednesday night, Conservative Leader Andrew Scheer said that Trudeau’s brownface photo was as racist in 2001 as it is today. 

“What Canadians saw this evening is someone with a complete lack of judgment and integrity and someone who is not fit to govern this country,” he said before walking away without taking any questions from reporters.

Over the weekend, Scheer had said that he will stand with Conservative candidates who have made controversial comments in the past, so long as they have apologized and taken responsibility for their comments.

NDP Leader Jagmeet Singh called Trudeau’s 2001 photo “troubling” and “insulting.”

“Any time we hear examples of brownface or blackface it's ... making a mockery of someone for what they lived and what their lived experiences are,” Singh said at a campaign event. “Racism is real. People in this room have felt it. I’ve heard the stories, I’ve experienced it in my life.”

In an emotional statement later Wednesday night, Singh directly addressed people who are personally impacted by the photo.

“The kids that see this image, the people that see this image are going to think about all the times in their life that they were made fun of, that they were hurt, that they were hit, that they were insulted,” he said.

“Seeing this image is going to be hard for a lot of people. It’s going to bring up a lot of pain … please reach out to your loved ones. Please reach out to people who are suffering in silence right now.”

Green Party Leader Elizabeth May tweeted that she is “deeply shocked by the racism shown in the photograph of Justin Trudeau.”

May said Trudeau must “commit to learning and appreciating the requirement to model social justice leadership at all levels of government. In this matter he has failed.”

The National Council of Canadian Muslims called the photo "deeply saddening.”

"The wearing of blackface/brownface is reprehensible, and hearkens back to a history of racism, slavery, and an Orientalist mythology that is unacceptable," said executive director Mustafa Farooq. The council later thanked Trudeau for his apology in a tweet.

In recent years, many politicians in the United States have had to apologize for appearing in blackface or brownface images. Some of those images also appeared in yearbooks from the past.

News of Trudeau’s brownface photo made international headlines on Wednesday. The New York Times and CNN were among the media outlets that featured stories on the controversy and predicted that the photo’s emergence will throw the Canadian election into “turmoil.”

With files from The Canadian Press